On many of my 3rd party jets, my speed seems to decrease above FL200 and continues to decrease until I stall or level out prior to my assigned altitude. Does anyone know what the problem is and how to fix it. It does not happen on the default aircraft.Thanks,Len

some of my aircraft just tend to go nose-up over fl200 even on autopilot. (wich of course also ends up in to low airspeed / stall )

Just out of curiosity, what sort of Fuel/payload are you carrying? Many long range aircraft require climbing to final altitudes in stages so that fuel is consumed and gross weight is therefore reduced. I know that a number of 3rd party A/C do take into consideration the actual engine power and gross weights of the planes and this might be what you are actually seeing. I have no idea what sort of research or parameters MS used with their larger A/C. I am aware that there have been numerous negative comments from some about the realism of some of the default A/C's performance; since the vast majority of the time, I'm flying add-on A/C and am not a real pilot, I can't really comment on that part. I do know that the 3rd party planes do have a more "real" feel to me at least, but you do have to read the directions and try to follow the procedures.Hope that's helpful.Best Regards,Ed Green, [email protected]

Up at those altitudes, use a constant Mach speed for the climb. As the air gets thinner up there, there is less air going through the pitot static system, thus giving you a lower IAS reading. Also, this means there is less air going over the wing, thus requiring a lower pitch attitude to keep the angle of attack below that at which it stalls. Less pitch means less vertical speed, so you'll just have to settle.And if you can't maintain a 500 fpm climb rate (to keep FS ATC happy), you're gonna have to step climb, which the post before this refered to.